Wound closure devices with dissolvable portions

ABSTRACT

A negative pressure wound closure system and methods for using such a system are described. Preferred embodiments of the invention facilitate closure of the wound by preferentially contracting to provide for movement of the tissue. Some embodiments may utilize a stabilizing structure with dissolvable portions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national stage application of International Patent Application No. PCT/EP2017/074255, filed Sep. 25, 2017, which claims priority to U.S. Provisional Patent Application No. 62/400,318, filed on Sep. 27, 2016 and U.S. Provisional Patent Application No. 62/511,157, filed on May 25, 2017. Each of these applications are hereby incorporated by reference in their entireties and made part of this disclosure.

BACKGROUND OF THE INVENTION Field of the Invention

This application describes embodiments of apparatuses, methods, and systems for the treatment of wounds, specifically to aid in the closure of large wounds, in conjunction with the administration of negative pressure. Some embodiments incorporate dissolvable portions to facilitate closure of the wound.

Description of the Related Art

Negative pressure wound therapy has been used in the treatment of wounds, and in many cases can improve the rate of healing while also removing exudates and other deleterious substances from the wound site.

Abdominal compartment syndrome is caused by fluid accumulation in the peritoneal space due to edema and other such causes, and results in greatly increased intra-abdominal pressure that may cause organ failure eventually resulting in death. Causes may include sepsis or severe trauma. Treatment of abdominal compartment syndrome may require an abdominal incision to permit decompression of the abdominal space, and as such, a large wound may be created onto the patient. Closure of this wound, while minimizing the risk of secondary infections and other complications, and after the underlying edema has subsided, then becomes a priority. However, acute open abdominal conditions may be caused by other reasons in addition to compartment syndrome, as described further below.

Other large or incisional wounds, either as a result of surgery, trauma, or other conditions, may also require closure. For example, wounds resulting from sterniotomies, fasciotomies, and other abdominal wounds may require closure. Wound dehiscence of existing wounds is another complication that may arise, possibly due to incomplete underlying fascial closure, or secondary factors such as infection.

Existing negative pressure treatment systems, while permitting eventual wound closure, still require lengthy closure times. Although these may be combined with other tissue securement means, such as sutures, there is also a risk that underlying muscular and fascial tissue is not appropriately reapproximated so as to permit complete wound closure. Further, when foam or other wound fillers are inserted into the wound, the application of negative pressure to the wound and the foam may cause atmospheric pressure to bear down onto the wound, compressing the foam downward and outward against the margins of the wound. This downward compression of the wound filler slows the healing process and slows or prevents the joining of wound margins. Additionally, inflammation of the fascia in the form of certain types of fasciitis can lead to rapid and excessive tissue loss, potentially meriting the need for more advanced negative pressure treatment systems. Accordingly, there is a need to provide for an improved apparatus, method, and system for the treatment and closure of wounds.

SUMMARY OF THE INVENTION

Embodiments of the present invention relate to negative pressure wound closure devices, methods, and systems that facilitate closure of a wound. It will be understood by one of skill in the art that the wounds described herein this specification may encompass any wound, and are not limited to a particular location or type of wound. The devices, methods, and systems may operate to reduce the need for repetitive replacement of wound filler material currently employed and can advance the rate of healing. The devices, methods, and systems may be simultaneously used with negative pressure to remove wound fluids.

Other embodiments of wound closure devices, stabilizing structures and associated apparatuses are described below.

In embodiments, a wound closure device comprises:

a stabilizing structure, comprising:

a plurality of cells provided side-by-side in a horizontal plane parallel to a length and width of the stabilizing structure, each cell defined by a plurality of walls extending in a vertical direction perpendicular to the horizontal plane; and

a plurality of dissolvable portions positioned within the cells, the dissolvable portions configured to dissolve over time.

In embodiments, the stabilizing structure is configured to collapse more in a horizontal plane parallel to a length and a width of the stabilizing structure than in a vertical plane perpendicular to the horizontal plane. In certain embodiments, the plurality of dissolvable portions prevent the stabilizing structure from collapsing, the stabilizing structure configured to collapse to a collapsed position when not prevented from collapsing.

The dissolvable portions may be configured to dissolve within 24 hours. In embodiments, the cells may be configured to be dissolvable. In certain embodiments, the cells may be configured to dissolve more slowly than the dissolvable portions. In some embodiments, the cells are configured to be not dissolvable.

The wound closure device may further comprise a suction port configured to supply negative pressure to a wound.

The wound closure device may further comprise a source of negative pressure.

The wound closure device may further comprise one or more drapes configured to cover the stabilizing structure and form a seal around a wound.

In embodiments, a wound closure device may comprise:

a stabilizing structure, comprising:

-   -   a plurality of cells provided side-by-side in a horizontal plane         parallel to a length and width of the stabilizing structure,         each cell defined by a plurality of walls extending in a         vertical direction perpendicular to the horizontal plane; and     -   a plurality of dissolvable portions positioned within the cells,         the dissolvable portions configured to dissolve over time.

The stabilizing structure may be configured to collapse more in a horizontal plane parallel to a length and a width of the stabilizing structure than in a vertical plane perpendicular to the horizontal plane.

In some embodiments, the plurality of dissolvable portions may prevent the stabilizing structure from collapsing, the stabilizing structure configured to collapse to a collapsed position when not prevented from collapsing.

The dissolvable portions may be configured to dissolve within 24 hours. The cells may be configured to be dissolvable. In certain embodiments, the cells are configured to dissolve more slowly than the dissolvable portions. The cells may be configured to not dissolve.

The dissolvable portions may comprise a carboxymethyl cellulose.

In some embodiments, the dissolvable portions may be positioned diagonally within the cells, the dissolvable portions extending from a corner of each cell to an opposite corner.

In some embodiments, the dissolvable portions may be coated on an interior face of each cell. The dissolvable portions may be coated on all four interior faces of each cell. The dissolvable portions may be positioned at intersections between walls within each cell.

In certain embodiments, a top layer of foam may be positioned above the stabilizing structure. A bottom layer of foam may be positioned under the stabilizing structure.

In particular embodiments, the top layer, or the bottom layer, or both layers of foam are coated in a dissolvable material.

The dissolvable portions may comprise thickened end portions. An outer surface of the stabilizing structure may comprise a biocompatible surface, the biocompatible surface configured to adhere to surrounding tissue. In certain embodiments, the stabilizing structure is configured to collapse under negative pressure.

The wound closure device of any one of the previous claims, further comprising a suction port configured to supply negative pressure to a wound.

The wound closure device of any one of the previous claims, further comprising one or more drapes configured to cover the stabilizing structure and form a seal around a wound.

The wound closure device of any one of the previous claims, further comprising a source of negative pressure.

Any of the features, components, or details of any of the arrangements or embodiments disclosed in this application, including without limitation any of the pump embodiments and any of the negative pressure wound therapy embodiments disclosed below, are interchangeably combinable with any other features, components, or details of any of the arrangements or embodiments disclosed herein to form new arrangements and embodiments.

The embodiments disclosed herein this application advantageously provide improved methods and apparatuses for wound closure.

Further features and advantages of at least some of the embodiments of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will be apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings of which:

FIG. 1 illustrates an embodiment of a negative pressure treatment system.

FIGS. 2A-C illustrate multiple views of an embodiment of a stabilizing structure.

FIGS. 3A-E illustrate multiple views of another embodiment of a stabilizing structure and a method of creating the stabilizing structure.

FIG. 4 illustrates an embodiment of a ring that can surround a stabilizing structure.

FIGS. 5A-D are photographs of embodiments of stabilizing structures with surrounding anchoring and foam layers.

FIGS. 6A-B are photographs of an embodiment of an anchoring layer.

FIG. 7 illustrates an embodiment of an open abdominal wound.

FIG. 8 illustrates an embodiment of a step in a method of treating a wound.

FIG. 9 illustrates an embodiment of a step in a method of treating a wound.

FIGS. 10A-C illustrate an embodiment of steps of a method of treating a wound.

FIGS. 11A-B are photographs of steps of a method of treating a wound.

FIGS. 12A-C depict an embodiment of steps of a method of treating a wound.

FIG. 13 contains photographs of embodiments of steps of a method of treating a wound.

FIGS. 14A-G illustrate an embodiment of a method of treating a wound.

FIG. 15A-E are photographs of an embodiment of a method of treating a wound.

FIG. 16 illustrates an embodiment of a stabilizing structure.

FIGS. 17A-E are drawings and photographs of an embodiment of a stabilizing structure.

FIGS. 18A-D illustrate an embodiment of a collapsed stabilizing structure.

FIGS. 19A-B illustrate embodiments of stabilizing structures.

FIGS. 20A-G illustrate embodiments of stabilizing structures and foam layers.

FIG. 21 illustrates an embodiment of a foam layer with fingers.

FIGS. 22A-E illustrate embodiments of a foam layer with printing.

FIGS. 23A-B present experimental data collected using embodiments of stabilizing structures and wound closure devices.

FIG. 24 illustrates am embodiment of a stabilizing structure with dissolvable portions.

FIGS. 25A-D illustrate an embodiment of a method of producing a stabilizing structure with dissolvable portions and the resulting structures.

FIGS. 26A-D illustrate an embodiment of a stabilizing structure with dissolvable portions.

FIG. 27A-B illustrates embodiments of a stabilizing structure with dissolvable portions.

FIG. 28 illustrates an embodiment of a stabilizing structure with dissolvable portions.

FIG. 29 illustrates an embodiment of a stabilizing structure with dissolvable portions.

FIG. 30 illustrates an embodiment of a stabilizing structure with dissolvable portions.

FIG. 31 illustrates an embodiment of a dissolvable portion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments disclosed in this section or elsewhere in this specification relate to apparatuses and methods of treating a wound with reduced pressure, including pump and wound dressing components and apparatuses. The apparatuses and components comprising the wound overlay and packing materials, if any, are sometimes collectively referred to in this section or elsewhere in this specification as dressings.

It will be appreciated that throughout this specification reference is made to a wound. It is to be understood that the term wound is to be broadly construed and encompasses open and closed wounds in which skin is torn, cut or punctured or where trauma causes a contusion, or any other superficial or other conditions or imperfections on the skin of a patient or otherwise that benefit from reduced pressure treatment. A wound is thus broadly defined as any damaged region of tissue where fluid may or may not be produced. Examples of such wounds include, but are not limited to, abdominal wounds or other large or incisional wounds, either as a result of surgery, trauma, sterniotomies, fasciotomies, or other conditions, dehisced wounds, acute wounds, chronic wounds, subacute and dehisced wounds, traumatic wounds, flaps and skin grafts, lacerations, abrasions, contusions, burns, electrical burns, diabetic ulcers, pressure ulcers, stoma, surgical wounds, trauma and venous ulcers or the like.

As is used in this section or elsewhere in this specification, reduced or negative pressure levels, such as −X mmHg, represent pressure levels that are below standard atmospheric pressure, which corresponds to 760 mmHg (or 1 atm, 29.93 in Hg, 101.325 kPa, 14.696 psi, etc.). Accordingly, a negative pressure value of −X mmHg reflects absolute pressure that is X mmHg below 760 mmHg or, in other words, an absolute pressure of (760−X) mmHg. In addition, negative pressure that is “less” or “smaller” than −X mmHg corresponds to pressure that is closer to atmospheric pressure (e.g., −40 mmHg is less than −60 mmHg). Negative pressure that is “more” or “greater” than −X mmHg corresponds to pressure that is further from atmospheric pressure (e.g., −80 mmHg is more than −60 mmHg).

The negative pressure range for some embodiments of the present disclosure can be approximately −80 mmHg, or between about −10 mmHg and −200 mmHg Note that these pressures are relative to normal ambient atmospheric pressure. Thus, −200 mmHg would be about 560 mmHg in practical terms. In some embodiments, the pressure range can be between about −40 mmHg and −150 mmHg. Alternatively, a pressure range of up to −75 mmHg, up to −80 mmHg or over −80 mmHg can be used. Also in other embodiments a pressure range of below −75 mmHg can be used. Alternatively, a pressure range of over approximately −100 mmHg, or even −150 mmHg, can be supplied by the negative pressure apparatus. In some embodiments, the negative pressure range can be as small as about −20 mmHg or about −25 mmHg, which may be useful to reduce fistulas. In some embodiments of wound closure devices described here, increased wound contraction can lead to increased tissue expansion in the surrounding wound tissue. This effect may be increased by varying the force applied to the tissue, for example by varying the negative pressure applied to the wound over time, possibly in conjunction with increased tensile forces applied to the wound via embodiments of the wound closure devices. In some embodiments, negative pressure may be varied over time for example using a sinusoidal wave, square wave, and/or in synchronization with one or more patient physiological indices (e.g., heartbeat).

Examples of such applications where additional disclosure relating to the preceding descriptions may be found include U.S. Pat. No. 8,235,955, titled “Wound treatment apparatus and method,” issued Aug. 7, 2012 and U.S. Pat. No. 7,753,894, titled “Wound cleansing apparatus with stress,” issued Jul. 13, 2010. Both applications are hereby incorporated by reference in their entirety. Other applications that may contain teachings relevant for use with the embodiments described in this section or elsewhere in this specification may include application Ser. No. 12/886,088, titled “Systems And Methods For Using Negative Pressure Wound Therapy To Manage Open Abdominal Wounds,” filed Sep. 20, 2010, published as US 2011/0213287; application Ser. No. 13/092,042, titled “Wound Dressing And Method Of Use,” filed Apr. 21, 2011, published as US 2011/0282309; and application Ser. No. 13/365,615, titled “Negative Pressure Wound Closure Device,” filed Feb. 3, 2012, published as US 2012/0209227, the entireties of each of which are hereby incorporated by reference. Still more applications that may contain teachings relevant for use with the embodiments described in this specification are application Ser. No. 13/942,493, titled “Negative Pressure Wound Closure Device,” filed Jul. 15, 2013, published as US 2014/0180225; PCT App. No. PCT/US2013/050619, filed Jul. 16, 2013 titled “Negative Pressure Wound Closure Device,” published as WO 2014/014871 A1; PCT App. No. PCT/US2013/050698, filed Jul. 16, 2013 titled “Negative Pressure Wound Closure Device,” published as WO 2014/014922 A1; PCT App. No. PCT/IB2013/01555, titled “Devices and Methods for Treating and Closing Wounds with Negative Pressure,” filed May 5, 2013, published as WO 2013/175309 A1; PCT App. No. PCT/US2014/025059, titled “Negative Pressure Wound Closure Device and Systems and Methods of Use in Treating Wounds with Negative Pressure,” filed Mar. 12, 2014, published as WO 2014/165275 A1; and PCT App. No. PCT/GB2014/050746, “Compressible Wound Fillers and Systems and Methods of Use In Treating Wounds With Negative Pressure,” filed Mar. 13, 2014, published as WO 2014/140578 A1, and “Negative Pressure Wound Closure Device,” filed Oct. 21, 2014, and published as PCT/US2014/061627. The entireties of the aforementioned applications are each hereby incorporated by reference and should be considered part of the present specification.

It will be understood that throughout this specification in some embodiments reference is made to an elongate, elongated or longitudinal strip or strips. It is to be understood that these terms are to be broadly construed and refer in some embodiments to an elongate material having two parallel or substantially parallel faces, where in cross-section a thickness of the material as measured perpendicular to the faces is relatively smaller than a height of the material measured parallel to the faces. While in some embodiments the strips may be constructed from discrete lengths of material, in other embodiments the strips may simply refer to elongate portions of an overall structure having two parallel or substantially parallel faces. The strips in some embodiments have a rectangular or generally rectangular-shaped faces, wherein a length of the face is longer than the height of the face. In some embodiments, the length of the face may be more than 2 times, 4 times, 6 times, 8 time, 10 times, 12 times or more greater than the height of the face.

As used in this section or elsewhere in this specification, the term “horizontal,” when referring to a wound, indicates a direction or plane generally parallel to the skin surrounding the wound. The term “vertical,” when referring to a wound, generally refers to a direction extending perpendicular to the horizontal plane. The term “longitudinal,” when referring to a wound, generally refers to a direction in the horizontal plane taken in a direction along which the wound is longest. The term “lateral,” when referring to a wound, generally refers to a direction in the horizontal plane perpendicular to the longitudinal direction. The terms “horizontal,” “vertical,” “longitudinal,” and “lateral” may also be used to describe the stabilizing structures and wound closure devices described throughout this specification. When describing these structures or devices, these terms should not be construed to require that the structures or devices necessarily be placed into a wound in a certain orientation, though in certain embodiments, it may be preferable to do so.

FIG. 1 illustrates an embodiment of a negative pressure treatment system 100 that comprises a wound packer 102 inserted into a wound 101. The wound packer 102 may comprise porous materials such as foam, and in some embodiments may comprise one or more embodiments of wound closure devices described in further detail in this section or elsewhere in this specification. In some embodiments, the perimeter or top of any wound closure device inserted into the wound 101 may also be covered with foam or other porous materials. A single drape 104 or multiple drapes may be placed over the wound 101, and is preferably adhered or sealed to the skin on the periphery of the wound 101 so as to create a fluid-tight seal. An aperture 106 may be made through the drape 104 which can be manually made or preformed into the drape 104 so as to provide a fluidic connection from the wound 101 to a source of negative pressure such as a pump 110. Preferably, the fluidic connection between the aperture 106 and the pump 110 is made via a conduit 108. In some embodiments, the conduit 108 may comprise a RENASYS® Soft Port™, manufactured by Smith & Nephew. Of course, in some embodiments, the drape 104 may not necessarily comprise an aperture 106, and the fluidic connection to the pump 110 may be made by placing the conduit 108 below the drape. In some wounds, particularly larger wounds, multiple conduits 108 may be used, fluidically connected via one or more apertures 106.

In some embodiments, the drape 104 may be provided with one or more corrugations or folds. Preferably, the corrugations are aligned along the longitudinal axis of the wound, and as such may support closure of the wound by preferentially collapsing in a direction perpendicular to the longitudinal axis of the wound. Such corrugations may aid in the application of contractile forces parallel to the wound surface and in the direction of wound closure. Examples of such drapes may be found in application Ser. No. 12/922,118, titled “Vacuum Closure Device,” filed Nov. 17, 2010 (published as US 2011/0054365), which is hereby incorporated by reference in its entirety.

In use, the wound 101 is prepared and cleaned. In some cases, such as abdominal wounds, a non- or minimally-adherent organ protection layer (not illustrated) may be applied over any exposed viscera. The wound packer 102 is then inserted into the wound, and is covered with the drape 104 so as to form a fluid-tight seal. A first end of the conduit 108 is then placed in fluidic communication with the wound, for example via the aperture 106. The second end of the conduit 108 is connected to the pump 110. The pump 110 may then be activated so as to supply negative pressure to the wound 101 and evacuate wound exudate from the wound 101. As will be described in additional detail below and in relation to the embodiments of the foregoing wound closure devices, negative pressure may also aid in promoting closure of the wound 101, for example by approximating opposing wound margins.

Any structure or component disclosed herein this section or elsewhere in the specification may comprise a radiopaque material. A radiopaque material advantageously allows a clinician to more easily find pieces of the wound closure device that may have come loose from the structure and become lost in the wound. Some examples of radiopaque materials include barium sulfate, bismuth trioxide, bismuth subcarbonate, bismuth oxychloride, and tungsten.

Stabilizing Structures and Wound Closure Devices of FIG. 2A-3E

FIG. 2A is a drawing of an embodiment of a stabilizing structure 6000 comprising a plurality of elongate strips 6006 arranged in parallel or semi-parallel, whose longitudinal length can be aligned with the longitudinal axis of a wound. In embodiments, the elongate strips 6006 may also be arranged in a non-parallel fashion. The various cells within this stabilizing structure 6000 may have a variety of shapes and sizes. As will be described in greater detail below, the length and shape of the elongate strips 6006, intervening members 6010, and cells 6004 may be designed so as to facilitate greater closure of the stabilizing structure. In certain embodiments, the junctions 6900 between the elongate strips and intervening members may be thinned to better facilitate rotation and closure of the stabilizing structures. In some embodiments, the stabilizing structure is tearable, such that the structure may be shaped into the shape of a wound. As described elsewhere in the specification, tears may be completed at the intersections between intervening members and elongate strips or at any suitable location along the elongate strip or intervening member.

All stabilizing structures described herein this section or elsewhere in the specification may be fashioned to accommodate any size of wound. However, to better accommodate the needs of the clinical environment, in certain embodiments, the stabilizing structures described herein may be provided in a pack of two sizes, one smaller stabilizing structure and one larger stabilizing structure about 1.25 times as larger, about 1.5 times as large, about 1.75 times as large, about 2 times as larger, about 2.5 times as larger, about 3 times as large, about 4 times as large, about 5 times as large, or more than about 5 times as large. In some embodiments, the pack may comprise more than two sizes, such as three sizes, four sizes, five sizes, or more than five sizes. The stabilizing structures within the pack may be of a variety of sizes in relation to one another such as the ratios described above.

In certain embodiments, the stabilizing structure 6000 can collapse in any manner described in this section or elsewhere in this specification with or without the application of negative pressure. For example, the stabilizing structure may collapse significantly more in one plane than in another plane upon application of negative pressure. In some embodiments, the stabilizing structure is configured to collapse more in a horizontal plane parallel to the length and width of the stabilizing structure than in a vertical plane perpendicular to the horizontal plane. In embodiments, particular rows may collapse in a first direction, while another row may collapse in the same or an opposing direction. In certain embodiments, the stabilizing structure may collapse along the width of the stabilizing structure while remaining relatively rigid along the length of the stabilizing structure and in the vertical direction.

The stabilizing structure may be comprised of any materials described in this section or elsewhere in this specification, including: flexible plastics such as silicone, polyurethane, rigid plastics such as polyvinyl chloride, semi-rigid plastics, semi-flexible plastics, biocompatible materials, composite materials, metals, and foam. In certain embodiments, the stabilizing structure may comprise a radio opaque material, to more readily allow a clinician to find pieces of the stabilizing structure within the wound.

Returning to FIG. 2A, stabilizing structure 6000 may have an outer perimeter that defines an at least partially elliptical shape. As described above, stabilizing structure 6000 may comprise a plurality of cells 6004 provided side-by-side, each cell defined by one or more walls, each cell having a top end and a bottom end with an opening extending through the top and bottom ends. As with the other stabilizing structures described herein this section and elsewhere in the specification, the stabilizing structure 6000 is configured to collapse by collapsing one or more cells 6004. In some embodiments, the cells are all of the same approximate shape and size; however, in other embodiments, the cells are of different shapes and sizes. In some embodiments, the stabilizing structures as described herein this section or elsewhere in the specification may be domed, such that the central portion of the stabilizing structure bulges upward. For example, a lower portion of the stabilizing structure may be concave, while an upper portion of the stabilizing structure is convex.

The elongate strips 6006 may be made from one single material, such as those described elsewhere in the specification, or the elongate strips may be made from multiple materials. For example, elongate strips 6006 may comprise sections of more rigid material and sections of more flexible material. The elongate strips 6006 may be curved along their length so as to facilitate the curved outer perimeter of the stabilizing structure 6000. The elongate strips may be curved along their lengths outward away from a center of the stabilizing structure 6000. The arch of the curves of the elongate strips 6006 may vary considerably, with some strips 6006 being highly curved while other are minimally curved or even straight.

Similarly, the stabilizing structure 6000 can further comprise a plurality of intervening members 6010 connected to the elongate strips 6006. The intervening members 6010 may all be of a similar shape and size or they may be of a variety of shapes and sizes. The intervening members may be constructed from any material disclosed herein this section or elsewhere in the specification. Further, the intervening members may be constructed from multiple materials.

Advantageously, the elliptical shape of stabilizing structure 6000 may allow the structure to better accommodate the shape of the wound. Most wounds are in shapes that are rounded, thus, an elliptically shaped stabilizing structure 6000 may better fit into a wound.

In embodiments, the outer perimeter 6002 may have a reduced edge 6012 so as to facilitate collapse of the stabilizing structure. By removing mass of the stabilizing structure at reduced edge 6012, the stabilizing structure can collapse more freely at reduced edge 6012, thus allowing for a better fit within the wound. Further, by reduced the mass at reduced edge 6012, there may be less pinching of the surrounding tissue during and after collapse of the stabilizing structure 6000.

The stabilizing structure 6000 and all stabilizing structures and wound closure devices described in this section or elsewhere in this specification can collapse on a variety of timescales in a dynamic fashion. In certain embodiments, the majority of the collapse may occur within the first few minutes upon application of negative pressure. However, after the initial collapse, the stabilizing structure or wound closure device may continue to collapse at a much slower rate, thereby applying increasing longitudinal tension over a long period of time and drawing the edges of the wound closer together. By slowly drawing the wound edges closer together over time, the stabilizing structure or wound closure device allows the surrounding healing tissue to remodel synergistically with the closure of the device or stabilizing structure. Slow, dynamic wound closure may allow the surrounding tissue to heal at an accelerated rate, because the collapsing structure or device slowly brings the edges of the wound closer together without stressing the newly formed or weakened tissue too quickly.

In some embodiments, the stabilizing structures described in this section or elsewhere in this specification can be placed into a wound for a period of time and then removed or replaced with another stabilizing structure. For example, a stabilizing structure could be inserted into a wound for a period of time, promoting closure of the wound by drawing the edges closer together. After a period of time has passed, the stabilizing structure can be replaced by a stabilizing structure of a different size or collapsibility, for example a stabilizing structure of a smaller size or decreased density. This process could be repeated over and over, thereby continuously drawing the edges of the wound together over time and allowing for continuing repair and remodeling of the surrounding tissue. In certain embodiments, the stabilizing structure is configured to remain in the wound for at least about less than 1 hour, at least about 1 hour, at least about 2 hours, at least about 4 hours, at least about 6 hours, at least about 8 hours, at least about 12 hours, at least about 24 hours, at least about 2 days, at least about 4 days, at least about 6 days, at least about 1 week, at least about 2 weeks, at least about 3 weeks, or more than 3 weeks.

In certain embodiments, up to 90% of the collapse of the stabilizing structure or wound closure device may occur within the first few minutes upon application of negative pressure, while the remaining 10% of the collapse may occur slowly over a period of many minutes, hours, days, weeks, or months. In other embodiments, up to about 80% of the collapse, up to about 70%, up to about 60%, up to about 50%, up to about 40%, up to about 30%, up to about 20%, up to about 10%, or about 0% of the collapse will occur immediately within the first few minutes upon application of negative pressure while the remainder of the collapse occurs at a much slower rate such as over the course of many minutes, hours, days weeks, or months. In other embodiments, the stabilizing structure can collapse at a variable rate. In some embodiments, the entirety of the collapse occurs at a slowed rate, while in other embodiments the entirety of the collapse occurs almost immediately within the first few minutes. In further embodiments, the collapse can occur at any rate and the rate can vary over time. In certain embodiments, the rate of collapse can be altered in a variable fashion by adding and/or removing portions of the structure or by controlling the application of negative pressure and irrigant fluid.

Returning to FIG. 2A, in some embodiments, the pattern of the stabilizing structure 6000 is designed in such a way as to facilitate maximum closure of the stabilizing structure. Preferably, maximum closure is in a direction perpendicular to the length of the elongate members and within the horizontal plane. As will be described in greater detail below, greater closure may be achieved by varying the length of the elongate strips 6006, the length of the intervening members 6010, and the shape of the cells 6004. The shape of the cells 6004 may comprise any shape described herein this section or elsewhere in the specification. For example, as depicted in FIG. 2A, the cells 6004 may be diamond-shaped or parallelepiped with smaller diamond-like shapes 6020 located within larger diamonds 6022. Such a construction may provide greater overall closure of the stabilizing device 6000 to provide for maximum closure of the wound. Additionally, the smaller diamond-like shapes 6020 located within larger diamonds 6022 can spread the load over a greater area reducing the chance of damage to the tissue structures below the matrix. This construction can also reduce the likelihood of the foam or the drape being pulled into the matrix and preventing closure of the wound.

FIGS. 2B-C are illustrations of different views of the stabilizing structure embodiment of FIG. 2A. As described above in relation to FIG. 2A, the stabilizing structure comprises cells 6004, intervening members 6010, and elongate strips 6006; however, here a simulated shape of a wound 6910 is also included for comparison.

Any of the stabilizing structures described herein this section or elsewhere in the specification may be constructed from any suitable means. For example, the stabilizing structures may be constructed via molding or may be printed directly using 3D printing technology. In certain embodiments, the stabilizing structures of FIGS. 2A-C may be constructed from a single polymer via 3D printing. In some embodiments, the stabilizing structures may be constructed from one polymer, two polymers, three polymers, or more than three polymers. The stabilizing structures may be constructed from any material disclosed herein this section or elsewhere in the specification. The stabilizing structure can be made by cutting the structure out of a solid block of material. Methods used for cutting can include, for example, water jet cutting, laser cutting, or die cutting. The stabilizing structures may be cut to size along the walls of the cells 6004. For example, the intervening members along the outside face of elongate strips 6006 can be cut off to appropriately size the stabilizing structure. The stabilizing structure may be cut along the walls, along any portions of the elongate strips, and/or along any portions of the intervening members.

In some embodiments, the stabilizing structure 6000 of FIGS. 2A-C can be configured to include perforations or detachable sections that allow portions of the device to separate from the remainder of the device. For example, perforations may be incorporated into the joints 6900 between various cells 6004 contained within the stabilizing structure 6000, allowing for the removal of individual rows or cells to alter the shape of the stabilizing structure 6000.

Applicable to all stabilizing structures or wound closure devices described in this section or elsewhere in the specification, the stabilizing structure or wound closure device may be tearable such that the stabilizing structure may be shaped into the shape of a wound. In some embodiments, the stabilizing structure may be torn at the intersections between intervening members and elongate strips, while in further embodiments, the elongate strips or intervening members may be torn at any suitable position.

FIGS. 3A-E depict methodologies for generating the design of a stabilizing structure, such as the stabilizing structures of FIGS. 2A-C. To facilitate various types of closure (for example, maximum closure) the shape, size, and location of the elongate strips, intervening members, and cells may be determined via various methods. For example, as depicted in FIG. 3A, each collapsible cell 6030 has four sides, and each intersection between an intervening member(s) and/or elongated strip(s) may be modeled via pin-joints 6032. Further, the entirety of stabilizing structure 6034 may be modeled inside of an oval wound model 6036. As depicted in FIG. 3A, the stabilizing structure 6034 may be modeled to collapse from an open state 6038 to a semi-collapsed state 6040, to a fully collapsed state 6042. In some clinical scenarios, maximum closure down to a completely flattened stabilizing structure may be desirable to maximize wound closure by drawing the edges of the wound as close together as possible.

As illustrated in FIG. 3B, in certain embodiments, the process of determining the optimal shape, size, and location of the elongate strips, intervening members, and cells for wound closure may be facilitated by modeling the stabilizing structure as a mirrored pattern on opposite sides of a mirror line 6050 (which may also be referred to as the transverse axis, perpendicular to a longitudinal axis of the stabilizing structure), thereby making the curve and collapse of the stabilizing structure symmetrical. The minor axis may be along the minor axis or it may be along the major axis of the stabilizing structure. Alternatively, the minor line may be located in any suitable location within the stabilizing structure, such as diagonally across the stabilizing structure. In certain embodiments, this method may lead to large diamond-shaped cells near the center line. These large diamond-shaped structures 6052 may be further subdivided to further support the stabilizing structure by including smaller diamond shapes 6054 within larger shapes. In some embodiments, these smaller shapes 6054 within a larger shape 6052 may comprise any shape disclosed herein this section or elsewhere in the specification. The larger cells may be further subdivided by two smaller shapes, three smaller shapes, four smaller shapes, or more than four smaller shapes. It will be understood by one of skill in the art that the minor line need not be confined to a line perpendicular to the longitudinal orientation of the wound. Instead, the mirror line may be located along the longitudinal axis of the wound or at an angle to the longitudinal axis of the wound. In some embodiments, the stabilizing structure may contain multiple mirror lines, thereby having multiple subsections that are symmetrical or different.

As illustrated in FIG. 3C, for a four-sided cell to collapse, it must follow a simple formula: a+b=c+d, where a, b, c, and d are the lengths of individual sides of a single cell within the stabilizing structure such as the cell 6060 of FIG. 3C. When members c and b collapse together, then d and a collapse together. Such a formula may be the basis for developing a pattern for a stabilizing structure that maximizes collapsibility.

FIG. 3D illustrates an expansion of the concept described in FIG. 3C. By using the base formula a+b=c+d, the elongate strips were progressively lengthened (a4>a3>a2>a1) towards the horizontal mirror line 6050, thereby achieving a curve in the stabilizing structure while preventing any of the intervening members 6062 from becoming perpendicular to the elongate strips 6064 (i.e. having an internal angle of 90 degrees). As illustrated in FIG. 3D, a value for b1 may be chosen, at which point an arbitrary offset value x may also be chosen to ease the construction of the various cell geometries. Using the progressive values for a1 through a4, illustrated visually in FIG. 3D 6066, values for b1-b4 may be calculated 6068. Using calculated values derived from equations 6068 for the various walls of the individual cells allows for the design of a stabilizing structure that collapses completely, such as those depicted in FIGS. 3A-B.

In some embodiments, a method for generating a stabilizing structure design may include steps to speed up the initial geometry construction. For example if all members from left to right in a specific row, as visualized by intervening members 6036 in FIG. 3E, a pattern then emerges where alternating vertical members are also the same length. Walls of the same length are indicated by their respective labels 6070, 6072, 6074, and 6076. Once the initial design is generated then individual cells may be modified by lengthening, shortening, removing or inserted according to the formulas of FIG. 3D to achieve the desired shape of the overall stabilizing structure.

The Anchoring Layers of FIGS. 4-6B

FIG. 4 illustrates an embodiment of an anchoring layer 4800 that may surround the stabilizing structures as described in this section or elsewhere in this specification. The ring 4800 can comprise a layer of tissue anchors 4802 configured to grip the surrounding edges of a wound. For example, the tissue anchors can be hooks, barbs, prongs, or other structures that serve to attach to the tissue of a wound. In certain embodiments, the tissue anchors comprise hook and loop fasteners such as those used in Velcro technologies. In certain embodiments, the ring 4800 can be comprised of foam, such as those described previously or the ring can be comprised of a combination of a foam layer and a tissue anchor layer 4802. A lip 4804 may extend inward from the ring 4800 and serve to overlap the top and/or the bottom of a stabilizing structure as described in this section or elsewhere in this specification, thereby securing the ring 4800 around the stabilizing structure.

FIGS. 5A-D are photographs of a wound closure device 5000 according to another embodiment. The wound closure device 5000 comprises a stabilizing structure 5002 which may be similar to the structures described in FIGS. 2A-3E, or may comprise any of the stabilizing structures described elsewhere in this specification. The stabilizing structure 5002 may optionally be surrounded by a porous layer 5004 such as a layer of foam, and the porous layer may be surrounded by an anchoring layer 5006 comprising tissue anchors such as those anchors produced by Velcro industries, various barbs and/or various hooks. In certain embodiments, the porous layer may be in the form of a ribbon. The stabilizing structure 5002, porous layer 5004 and anchoring layer 5006 may be provided as separate components to be attached by the practitioner in use, or they may be pre-attached to each other.

Similar to the embodiments illustrated in FIGS. 2A-3E, the stabilizing structure 5002 can collapse in any manner described elsewhere in this specification, for example, horizontally. When the wound closure device 5000 is implanted, the surrounding tissues can be pressed against the tissue anchors to embed them within the tissue and anchor the device. In some embodiments, the wound closure device 5000 may be placed in a wound and sealed with a drape. Although the embodiments further described in this section comprise an anchor layer that surrounds a porous layer, other embodiments may omit the porous layer, such that the anchoring layer directly surrounds or is attached to the stabilizing structure.

In some embodiments, the anchoring layer 5006 comprises an elongate strip of material comprising a plurality of tissue anchors extending from a base layer 5007, wherein the tissue anchors can have different shapes and sizes as described elsewhere in the specification. The tissue anchors may extend from a first planar side of the elongate strip, and the second planar side of the elongate strip may comprise an adhesive covered by an adhesive backing layer. The structure of the anchors can have various forms depending on the tissue they are intended to bind. Longer anchors can be used for loosely bound tissues such as fat or connective tissue, while shorter anchors can be used for denser tissues such as muscle. In other embodiments, depending upon the shape of the anchor, shorter anchors may be more desirable for softer, fatty tissue, while longer anchors are utilized for denser tissues. Anchors with more rigid stems can be utilized to penetrate denser tissues. In some embodiments, anchors can have bilateral prongs that tend to collapse upon insertion in tissue and yet expand when pulled in an opposite direction such that a certain pulling force can be applied to tissue. The characteristics of the anchors or attachment mechanisms, and their resulting force profiles, can vary by a number of parameters, such as the length of the anchor, the shape of the attachment mechanisms, the structure of grasping features, the material(s) used for the attachment mechanisms, the relative flexibility/rigidity of the attachment mechanisms, and the spacing/density of the attachment mechanisms.

The anchors may have various lengths for optimal penetration of the surrounding tissue. For example, the length of the anchors may be at most about 0.01 mm, at most about 0.1 mm, at most about 0.2 mm, at most about 5 mm, at most about 1 mm, at most about 2 mm, at most about 3 mm, at most about 5 mm, at most about 10 mm, at most about 20 mm, at most about 30 mm, at most about 40 mm, at most about 50 mm, at most about 75 mm, at most about 100 mm, or more than 100 mm.

FIG. 5B is a photograph of a closer view of the anchoring layer 5006 of the wound closure device 5002 depicted in FIG. 5A. The anchoring layer may consist of a first band of longer anchors 5008 configured to surround the porous layer 5004 and stabilizing structure 5002, and a second band of shorter anchors 5010 configured to surround the porous layer 5004 and stabilizing structure 5002. As illustrated, the first band 5008 may be disposed above the second band 5010. In some embodiments, there may be additional alternating series of bands vertically relative to each other. In further embodiments, the different bands may have different anchor lengths and shapes, as disclosed herein this section and elsewhere in the specification. For example, instead of 2 types of bands with 2 types of anchors, there may be 3 types of band with 3 types of anchors or 4 types of bands with 4 types of anchors and so on. Preferably, the anchors are selected for the appropriate tissue types. For example, returning to FIG. 5B, the first band 5008 may comprise longer anchors, desirable for penetration into the denser fascia, and thus may be positioned towards the bottom of the device. Similarly, the second band 5010 comprises shorter double hooks, desirable for penetration into denser tissue. Other suitable tissue anchors, as described elsewhere in this specification, include the hook and loop configuration of Velcro, barbs, hooks, spikes, pegs, arrowheads, or any suitable shape. Further examples of surfaces include textured surfaces, such as roughened sandpaper-like surfaces, or nano-textured surfaces that may facilitate tissue adhesion.

In some embodiments, the use of surface anchors can be used in combination with a surgical adhesive, providing a much stronger bond between tissue layers than the adhesive alone, and providing temporary adhesion while the adhesive sets. In some embodiments, the surgical adhesive can be added to the anchors themselves. In certain embodiments, the surgical adhesive may simply be applied between the anchors to coat at least a portion of the anchoring layer. In further embodiments, the anchors may be replaced with a surgical adhesive, and the surgical adhesive may act to anchor the device to the surrounding wound.

In certain embodiments, the anchors may be constructed from a variety of materials, including any materials disclosed elsewhere in the specification, such as: synthetic or natural polymers, metals, ceramics, or other suitable materials. The anchors may be constructed from biodegradable materials such as biodegradable synthetic or natural polymers. Non-limiting examples of biodegradable synthetic polymers include: polyesters such as polylactic acid or polyglycolic acid, polyanhydrides, and linear polymers with biodegradable linkages. Further, the anchors may be constructed of biodegradable biological materials, such as autografts, allografts, and/or xenografts.

FIG. 5C is a photograph of an embodiment of a wound closure device 5000, similar to the wound closure devices of FIGS. 5A-B. However, in this orientation the first band 5008 of anchors is towards the bottom of the device, while the second band of anchors 5010 is towards the top. As described above, the bands of anchors may be arrayed in any desired manner. FIG. 5D is a top view of an embodiment of a wound closure device 5000, similar to the wound closure devices of FIGS. 5A-C.

Considering the anchoring layer of FIGS. 5A-D, the shape of the anchoring layer is not limited to the ring shape of FIG. 4. In some embodiments, the anchoring layer is wrapped around the entirety of the stabilizing device, i.e. the top, bottom, and sides. In other embodiments, the anchoring layer is only around a portion of the perimeter of the stabilizing structure. In certain embodiments, the anchoring layer is only attached to discrete portions of the stabilizing structure as needed. In some embodiments, the anchoring layer covers at most about 5%, at most about 10%, at most about 20%, at most about 30%, at most about 50%, at most about 75%, and at most about 100% of the outside of the stabilizing structure.

In some embodiments, the bands of different tissue anchors can be organized in a vertical direction, while in other embodiments, they may be organized in a horizontal direction. They may also be organized in either the horizontal and vertical directions when considered in the xy plane, i.e. facing downward into the wound.

In certain embodiments, the different types of anchors may be interspersed with one another, rather than organized into discrete bands of specific types of anchors. For example, the longer anchors may be surrounded by smaller anchors and vice-versa. In some embodiments, the anchors may be organized randomly across the anchoring layer or in other suitable patterns.

In particular embodiments, the anchoring layer may be disposed on the inner faces of the stabilizing structure. For example, the anchoring layer may cover at most about 5%, at most about 10%, at most about 20%, at most about 30%, at most about 50%, at most about 75%, and at most about 100% of the interior surfaces of the stabilizing structure.

In further embodiments, the entire anchoring layer may be comprised of only one type of anchor, for example the entirety of the anchoring layer may be comprised of the longer hooks 5008 or the shorter hooks 5010 as depicted in FIG. 5B. Some embodiments may call for the anchors to be color coded. For example, the anchors on the bottom may be made to be one color while the anchors on the top may be another so as to identify the proper orientation of the stabilizing structure in the wound.

FIGS. 6A-B are pictures of embodiments of an anchoring layer 12000 with anchors 12008, similar to the anchors depicted in FIGS. 5A-D. Examples of such anchors may be available from Alfatex. In one embodiment, an anchoring layer may be provided comprising a 3D fabric material or portion thereof. For example, a 3D fabric may comprise a woven fabric layer provided along a first plane and a plurality of monofilaments extending perpendicularly from or at an angle relative to the woven fabric layer. The woven fabric layer may be configured to be attached to directly or indirectly to the outside of a stabilizing structure as described elsewhere in this specification and in the applications incorporated by reference. Monofilaments may have a mushroom-shaped head or other shapes configured to engage tissue surrounding the stabilizing structure. The head of the monofilaments may be similar to a peened rivet with a flatted head and extended edges that engage the surrounding tissues. If the monofilaments protrude at an angle then the material creates more grip in one direction of shear than another. This directionality means the anchoring layer and monofilaments can be positioned on a stabilizing structure so that the shear acts to stop the device being forced up or out of the wound by the viscera but can be easily released by pushing it down.

Wound Closure and Treatment Methods of FIGS. 7-15E

The stabilizing structures and/or wound closure devices described in this section or elsewhere in this specification may be used in conjunction with methods or systems for the closure of a wound. In some embodiments of methods of use for closure of a wound, one or more of the stabilizing structures or wound closure devices of any of the embodiments described in this section or elsewhere in this specification is placed into a wound. In some embodiments, an organ protection layer may be provided in the wound before placement of the stabilizing structure. In certain embodiments, foam or other porous material may be placed in the wound along with the stabilizing structure or wound closure device, either below, above, or surrounding the stabilizing structure or wound closure device. Foam or other porous material may also surround the perimeter of the stabilizing structure or wound closure device. The stabilizing structure or wound closure device may be configured to collapse in any manner as described in this section or elsewhere in this specification, for example by having a particular size and shape, or by comprising a certain volume of foam or other porous material within the cells of the structure. The stabilizing structure or wound closure device may further be altered in any manner described in this section or elsewhere in this specification so as to better accommodate the shape of the wound. After placement in the wound, the stabilizing structure or wound closure device can be sealed by a fluid-tight drape. The fluid-tight drape can comprise a port configured for the application of negative pressure. A source of negative pressure may then be connected to the port and negative pressure may be applied to the wound. The stabilizing structure or wound closure device may be replaced over time by stabilizing structures or wound closure devices of various shapes and sizes as desired to best promote wound healing.

FIGS. 7-15E are photographs and illustrations depicting embodiments of methods for the treatment of a wound that utilize a wound closure device comprising a stabilizing structure as described herein this section and elsewhere in the specification. To better illustrate non-limiting embodiments of the methods, numbers have been added to the steps of FIG. 13 to allow the reader to more easily follow these steps of the method. However, the steps can be performed in any order, and any numbering system is for clarity only. Further, in some embodiments, different steps of these methods may be excluded. In other embodiments, additional steps may be added to the methods based on methods described herein this section and elsewhere in the specification. The porous layers and structures described in this section may be of any material or structure described elsewhere in the specification, such as foam.

FIG. 7 depicts an embodiment of an open wound 5100 prior to treatment with a wound closure device as will be described in much greater detail below. The open wound of FIG. 6 is similar to the wounds described elsewhere in the specification, particularly as relate to FIG. 1. In some instances, as described elsewhere in the specification, such a wound may be produced via a surgical incision or other means.

FIG. 8 depicts an embodiment of an initial step in a method for the treatment of an open wound 5100 with a wound closure device. Before treatment, the wound may be cleaned with a pad 5180 and the skin 5190 prepared for application of a wound closure device, such as those described in relation to FIGS. 2A-3E.

FIG. 9 depicts an embodiment of an early step in a method for the treatment of an open wound 5100. In some embodiments, a tissue protection layer 5170 may be placed over the wound to protect the underlying tissues from the rigors of negative pressure wound therapy or other potential harms. Accordingly, certain embodiments provide for a tissue protection layer 5170 which may be cut to size to be placed over the wound site 5100. The tissue protection layer 5170 can be a material which will not adhere to the wound site or to the exposed viscera in close proximity. Such a tissue protection layer may be constructed from any suitable material such as a biocompatible polymer. For example, organ protection layers manufactured by Smith & Nephew and sold under the brand RENASYS® may act as tissue protection layers and be placed over the abdominal cavity and/or wound bed 5100 and tucked over the peritoneal gutter. In further examples, materials such as the fluoropolymer polytetrafluoroethylene (PTFE) may be applicable as these materials are generally non-adherent and used in surgical grafts. In one embodiment, the tissue protection layer is permeable. For example, the tissue protection layer 5170 can be provided with openings, such as holes, slits, or channels, to allow the removal of fluids from the wound site 5100 or the transmittal of negative pressure to the wound site 5100. In further embodiments, the tissue protection layer may be used over non-abdominal wounds on other areas of the body, such as the leg, arm, shoulder, or back. In certain embodiments, the tissue protection layer may comprise a sensor configured to measure pressures in and around the wound. For example, the sensor may be used to measure the level of negative pressure applied to the wound or to measure the pressure on the underlying organs beneath the abdominal wound.

FIGS. 10A-C illustrate embodiments of possible initial steps in a method for the treatment of an open wound. However, as described above, the steps need not be performed in this order and may be performed in any order. In FIG. 10A, two pieces of a porous material such as foam, a bottom piece 5102 and a top piece 5116 are selected so as to approximate the size of the wound 5100. In some embodiments, the top piece and the bottom piece are of identical thickness. However, in certain embodiments, and vice-versa, top piece 5116 may be at least twice as thick, at least four times as thick, at least 10 times as thick or more than ten times as thick as bottom piece 5102. FIG. 10B illustrates an embodiment of additional steps in a method for the treatment of an open wound. Bottom piece 5102 may be shaped via cutting or other suitable means to the shape of the wound and subsequently placed into the wound 5100, as shown in FIG. 10C and depicted further below in FIG. 11A.

FIGS. 11A-B are photographs of a foam layer 5102 (for example, a 15 mm layer of foam), after shaping, placed into a wound bed 5100. In FIGS. 12A-C, a stabilizing structure 5104 similar to the stabilizing structures disclosed in FIGS. 2A-3E or any other stabilizing structure described elsewhere in the specification, is in the shape of the wound. The stabilizing structure may be shaped into the shape of the wound via cutting or other suitable means or the stabilizing structure may initially be of a size that is readily accommodated by the wound. As displayed in FIG. 12B, the stabilizing structure 5104 may be placed into the wound. To assist with the insertion of the device into the wound bed, the device can be deformed slightly inwardly or horizontally to facilitate entrance into the wound site. In some embodiments, the device may be squeezed slightly during insertion and then release upon contact with the walls of the wound. In certain embodiments, the wound closure device 5104 may be placed such that the longitudinal sides of the matrix align with the longitudinal axis of the wound 5100. Continuing with FIG. 12B, another foam layer 5116 (for example, a 10 mm layer of foam) is placed on top of the wound closure device 5104.

FIG. 12C is a photograph of application of a port 5122 to the stabilizing structure and foam of FIGS. 12A-B. A bridging portion of foam 5118 may be placed in intimate contact with the foam layer 5116 at the edge of the wound. The bridging portion of foam 5118 may extend over intact skin, with a piece of drape 5120 placed between it and the intact skin. Further, a suction port 5122 may be connected to the bridging portion 5118 with a section of drape 5120 between. In alternative embodiments, the bridging portion 5118 and suction port 5122 may be placed on the wound during a different step depicted in FIGS. 11A-12B.

In FIG. 13, as shown by steps 1-4, the device may be covered by one or more drapes 5120. A hole may be made in the drape covering the bridging portion of foam, and a suction port 5122 may be placed over the hole. A protective layer 5124 on the top surface of the one or more drapes may be removed after the drapes 5120 are applied. Once the drapes 5120 are applied and the port is in place, negative pressure may be applied to the wound through the drape from a vacuum source. The negative pressure can cause the stabilizing structure to collapse horizontally as described elsewhere in this specification. The tissue anchors adhered to the stabilizing structure through the porous layer engage tissue of the wound and may facilitate closure of the wound.

In certain embodiments, the suction port may be placed directly over the central portion of the foam layer 5116. In such embodiments, the foam layer may collapse inward along with the stabilizing structure while under negative pressure, thereby collapsing the suction port. To avoid collapse, the suction port may be rigid in comparison to the foam and resist collapse. A washer may be placed inside, below, or around the suction port to provide rigidity and resist collapse.

In some embodiments, the suction port may be pre-attached to the top foam layer so that drapes can be positioned around the port. A hard port or a soft port may be used, such ports may further be used in combination with a washer such as described above. In further embodiments, the suction port could only partially collapse with the collapsing matrix while still maintaining the port opening for negative pressure.

FIGS. 14A-14C provide further illustrations of an upper foam layer 5116 being placed in a wound, followed by placing a bridging portion 5118 and placing one or more drapes or wound covers 5120. FIGS. 14D-14G illustrate an embodiment of several steps in a method for the treatment and closure of a wound. As illustrated in FIG. 14D, a suction port 5122 is separated from a release liner 5126 and later applied to a wound as depicted in FIGS. 11A-13. FIG. 14E illustrates a canister 5128 being inserted into a negative pressure wound therapy device 5130 in preparation for the collection of wound exudate. FIG. 14F illustrates the snap connection between the tubing connected to the suction port and the tubing connected to the negative pressure wound therapy device 5130. Once the connection has been made, negative pressure wound treatment may begin as depicted in FIG. 14G.

FIGS. 15A-E are photographs and a drawing of a prior art or alternative method for closing a wound, with some similarities to the methods of FIGS. 7-14G. Here, foam is placed under the muscle and fascia, followed by foam extending vertically out of the wound and folded over. Such a method may provide enhanced closure of the dermis but possibly not at the fascia level. In alternative embodiments, such a configuration may be combined with a stabilizing structure such as those disclosed herein this section and elsewhere in the specification, by providing a folded over foam layer 5116 that bulges out of the wound. FIG. 15E is a cross-sectional drawing of the prior art or alternative method.

Further details regarding the wound closure devices, stabilizing structures, related apparatuses and methods of use that may be combined with or incorporated into any of the embodiments described herein are found elsewhere throughout this specification and in International Application No. PCT/US2013/050698, filed Jul. 16, 2013, published as WO 2014/014922 A1, the entirety of which is hereby incorporated by reference.

The Stabilizing Structures of FIGS. 16-19D

FIG. 16 is a drawing of an embodiment of a stabilizing structure 6100, similar to the stabilizing structures of FIGS. 2A-3E. Stabilizing structure 6100 may be constructed via any means described herein this section or elsewhere in the specification, such as via 3D printing and via the calculation method described in FIGS. 3A-3E. Further, stabilizing structure 6100 may be constructed from any material described herein this section or elsewhere in this specification such as the materials described in relation to FIGS. 2A-3E. Similar to the stabilizing structures of FIGS. 2A-3E, stabilizing structure 6100 comprises a plurality of elongate strips 6106 arranged in parallel or semi-parallel, whose longitudinal length can be aligned with the longitudinal axis of a wound. In embodiments, the elongate strips 6106 may also be arranged in a non-parallel fashion. The various cells within this stabilizing structure 6100 may have a variety of shapes and sizes. As was described in greater detail above, the length and shape of the elongate strips 6106, intervening members 6110, and cells 6104 may be designed so as to facilitate greater closure of the stabilizing structure.

In embodiments, the stabilizing structure of FIG. 16 differs from the stabilizing structures of FIGS. 2A-3E, due to the inclusion of an extended section 6120. Extended section 6120 comprises one or more additional cells that extend outward along the longitudinal axis of the stabilizing structure 6100. Extended section 6120 may allow the stabilizing structure to better fit within a long incisional wound. Further, the addition of extended section 6120 may serve to prevent pinching of the surrounding tissue during collapse of the stabilizing structure 6100. Extended section may comprise about 6 additional cell, 12 additional cells, 16 additional cells, 20 additional cells, 30 additional cells, or more than 30 additional cells.

As depicted in FIG. 16, extended section 6120 may include additional rows having progressively fewer cells across its width. For example, extended section 6120 may comprise a row of four cells, then a row of two cells, followed by another row of two cells. In some embodiments, a row of six cells precedes the row of four cells. The extended section 6120 extends beyond the outer edge of a virtual ellipse formed by the majority of the perimeter of the stabilizing structure along the longitudinal axis of the stabilizing structure. In certain embodiments, the extended section may extend from both ends of the stabilizing structure along the longitudinal axis. The extended section 6120 in some embodiments provides a stepped outer perimeter to the outer wall of the stabilizing structure at the longitudinal edges of the stabilizing structure, in contrast to the continuous outer perimeter along the sides of the stabilizing structure 6122.

Absent the extended section 6120, the stabilizing structure comprises non-stepped side walls along substantially the entire length of the oval. However, with the extended section, the additional rows may provide a stepped outer perimeter 6124 based on the additional rows, in contrast to the flattened oval end of the stabilizing structure 6126. Further embodiments of the extended section will be described in more detail below in relation to FIGS. 17A-17E.

FIGS. 17A-17E are drawings and pictures of embodiments of stabilizing structure 6200, similar to the stabilizing structures of FIGS. 2A-3E and FIG. 16. Much like the stabilizing structures disclosed elsewhere in the specification, stabilizing structure 6200 comprises elongate strips 6206, cells 6204, and intervening members 6210. Stabilizing structure 6200 further comprises extended sections 6220 at both ends of the longitudinal axis of the stabilizing structure. As described above in relation to FIG. 16, extended sections 6220 may allow the stabilizing structure to better fit within the contours of a wound. Further, extended sections 6220 may prevent pinching of the surrounding tissue after collapse of the stabilizing structure. As described above, extended section may comprise multiple cells.

The stabilizing structures of FIGS. 17A-17E, and any of stabilizing structure disclosed herein this section or elsewhere in the specification may be produced in a variety of sizes. The possible size and shape of an actual wound may vary dramatically in size and shape, thus suitable stabilizing structures may also be prepared in a variety of sizes. For example, the length of an un-collapsed stabilizing structure may be approximately at least 25 mm, 50 mm, 75 mm, 100 mm, 125 mm, 150 mm, 175 mm, 200 mm, 250 mm, 300 mm, 350 mm, 400 mm, 450 mm, 500 mm, 750 mm, or greater than 750 mm. In certain embodiments, the width of an un-collapsed stabilizing structure may be at least 10 mm, 15 mm, 25 mm, 35 mm, 50 mm, 75 mm, 100 mm, 125 mm, 150 mm, 175 mm, 200 mm, 250 mm, 300 mm, 350 mm, 400 mm, 450 mm, 500 mm or greater than 500 mm.

As depicted in FIG. 17E, in some embodiments the un-collapsed stabilizing structure may have a length of approximately 242 mm. However, the stabilizing structure may be of any size disclosed herein this section or elsewhere in the specification. The cells 6204 of the stabilizing structure may be of a variety of sizes, for example the width of a cell 6204 may be approximately at least 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 50 mm, or more than 50 mm. For example, the length of a cell may be approximately at least 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 50 mm, or more than 50 mm.

In some embodiments, extended sections 6220 may comprise a first row of four cells, followed by a row of two cells, followed by another row of two cells. The row of four cells may be preceded by a row of six cells. However, in further embodiments, the extended section may comprise various numbers of cells per row and different numbers of rows. For example, extended section may comprise 1 row, 2 rows, 3 rows, 4 rows, 5 rows, 6 rows, or more than 6 rows. In embodiments, the rows may comprise 1 cell, 2 cells, 3 cells, 4 cells, 5 cells, 6 cells, 8 cells, 10 cells, 16 cells, or more than 16 cells.

Returning to FIG. 17A, in certain embodiments, the extended section may comprise a series of cells 6104 comprising walls that are semi-parallel 6230 to the longitudinal axis of the stabilizing structure. These cell walls contrast with cell walls elsewhere in the stabilizing structure which comprise walls that run at an angle 6240 to the longitudinal axis of the stabilizing structure 6200.

In embodiments of the stabilizing structure comprising extended sections 6220, elongate members 6206 closest to the central longitudinal axis of the stabilizing structure extend further along the longitudinal axis than embodiments of the stabilizing structure that do not comprise an extended section. For example, the innermost elongate strips are the longest strips, while the next innermost strips are the second longest and so on. The presence of the extended sections causes the stabilizing structure when viewed from above to appear to be more eye-shaped rather than more oval-shaped.

As depicted in FIG. 17A-C, in embodiments, the stabilizing structure 6200 may be oculiform. An oculiform shape may appear to be shaped like a human eye, with curved upper and lower edges converging to points at either longitudinal pole in the corners of the eye. Here, the outer walls curve inward 6250 to converge at the extended sections 6220. This shape is in contrast to a more diamond shape (not shown) where the outer walls would converge in a straight line to extended section 6220. However, in some embodiments, the stabilizing structure may be in the form of a diamond, rather than an oculiform.

Stabilizing structure 6200 further comprises tabs 6212 extended outward from the outer wall of the stabilizing structure 6200. Such tabs may extend outward from the top or the bottom of the stabilizing structure or both. The tabs may extend out from all outer cells of the stabilizing structure as depicted by FIG. 17C or the tabs may alternate as depicted in FIG. 17A. FIG. 17D is a photograph of a close up view of a tab 6212. The tabs may be constructed from any material described herein this section or elsewhere in the specification, such as those materials used for construction of the stabilizing structures. In certain embodiments, the tabs may be 3D printed as part of the stabilizing structure.

The tabs 6212 may further comprise an anchoring layer, such as those described above in relation to FIGS. 4-6B. This anchoring layer may be used to adhere the tabs to a layer of foam. In embodiments, the tabs may be coated in a suitable adhesive, allowing the tabs to be adhered to a layer of foam. The attachment of foam to the upper and lower layers of the stabilizing structure will be described in greater detail below in relation to FIG. 20A-22E. The tabs may further serve to extend outward above or below tissues surrounding the stabilizing structure or around other structures such as foam, wrapped around the perimeter of the stabilizing structure.

The stabilizing structures of FIGS. 17A-17E may be provided in a variety of sizes such as those described above in relation to FIGS. 2A-3E. As described above, it may be advantageous in a clinical setting to minimize adjustments to the size of the stabilizing structure, therefore a kit may be provided that includes stabilizing structures of various sizes that may be fit to a wound of the appropriate size. For example, the kit may comprise only two sizes of matrices, a large size and a small size. The larger size stabilizing structure may be at least about 1.25×, 1.5×, 1.75×, 2×, 2.5×, 3×, 4×, 5×, 6× or greater than 6 times the size of the smaller stabilizing structure.

FIGS. 18A-D are photographs of multiple views of the stabilizing structure 6200 of FIG. 17B, in a collapsed state. During collapse, the length and height of the stabilizing structure remain approximately the same while the width decreases dramatically. As described above, the stabilizing structure may collapse in such a manner when subjected to negative pressure, thereby facilitating closure of the wound. As shown in FIG. 18A, in some embodiments, the extended sections 6220 may avoid collapse, however as shown in FIGS. 18C-D, in embodiments the extended section will collapse along with the remainder of the stabilizing structure.

FIGS. 19A-B depict further embodiments of stabilizing structures 6300, similar to the stabilizing structures disclosed herein this section or elsewhere in the specification. The pattern of the stabilizing structures of FIGS. 19A-B comprises a series of cells symmetrically oriented around a mirror line 6302 along the minor axis of the stabilizing structure. In embodiments, the stabilizing structure of FIG. 19A has an un-collapsed width of 300 mm and a length of approximately 510 mm, while the stabilizing structure of FIG. 19B may have an un-collapsed width of 242 mm and length of 343 mm. The largest cells of the stabilizing structure of FIG. 19B may have a width of 30 mm. However, it will be understood by one of skill in the art that the stabilizing structures of FIGS. 19A-B may comprise any size and shape disclosed herein this section or elsewhere in the specification.

The Stabilizing Structures and Foam Layers of FIGS. 20A-22E

FIGS. 20A-22E are drawings and photographs of foam layers in combination with stabilizing structures such as those described above in relation to FIGS. 2A-3E and 16-19B. The foam layers described below may include any type of foam described herein this section or elsewhere in the specification. Possible foams may include open-celled and/or reticulated foams made from a polymer. Suitable foams include foams composed of, for example, polyurethane, silicone, hydrophobic materials, hydrophilic materials, open-celled materials, close-celled materials, mixed open and close-celled materials, reticulated materials, polyester, silicone, and/or polyvinyl alcohol. In embodiments, the foam layers described herein may include materials that change their properties over time. For example, a particular foam may be rigid initially but become more flexible when wet and/or lose rigidity over time due to degradation of the material.

The foam layers described in this section or elsewhere in the specification may have a variety of suitable thicknesses. For example, a foam layer may have a thickness of at least about 1 mm, 3 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, or more than 50 mm thick. Single layers of foam may be laid atop one another to create a greater total thickness of foam, for example, a 15 mm thick layer of foam may be laid atop a 10 mm layer of foam to create a 25 mm total thickness of foam.

In certain embodiments, any of the foam layers described herein this section or elsewhere in the specification, may be pre-attached to an organ protection layer such as described above. For example, the lowest layer of foam, closest to the underlying organs, may be attached to an organ protection layer before placement within the wound, thereby saving the clinician the step of first placing an organ protection layer within the wound. In certain embodiments, the organ protection layer may be pre-attached to the underside of a stabilizing structure such as those described herein this section or elsewhere in the specification. In embodiments, the organ protection layer may be attached to the top of the bottom-most foam layer placed in the wound, thereby positioning the organ protection layer between the stabilizing structure and the bottom-most layer of foam. The organ protection layer may completely encase the bottommost layer of foam or stabilizing structure. The presence of a bottom layer of foam and/or organ protection layer may serve to protect the underlying bowel from damage due to direct interaction with the stabilizing structure.

FIGS. 20A-D are drawings and photographs of embodiments of a wound closure device 6350 comprising a stabilizing structure 6302 (similar to the stabilizing structures described above in relation to FIGS. 2A-3E and 16A-19D), a top porous foam layer 6352, and a bottom porous foam layer 6354. As will be described in greater detail below, top and bottom porous layers 6352 and 6354 may be shaped in any desired manner to conform to the shape of stabilizing structure 6302. In embodiments, the top and bottom layers of foam may be attached to the stabilizing structure 6302 before placement in the wound. Pre-attachment of the foam layers advantageously reduces the number of steps that need to be completed by the clinician

As described elsewhere in the specification, stabilizing structure 6302 may comprise tabs 6304. These tabs advantageously provide a larger surface area for attachment of the foam layers to the stabilizing structure. Without the tabs, adhesive would necessarily need to be applied to the narrow upper edges of the stabilizing structure, potentially creating a weak or non-existent attachment. As described above, the tabs may be located on the top and bottom edges of the stabilizing structure. In embodiments, rather than adhesive, the tabs may be covered in anchors, such as those described above in relation to FIGS. 4-6B. The anchors act much like the adhesive, allowing the foam layers to be attached to the stabilizing structure prior to placement in the wound. The stabilizing structure may be pre-attached to the bottom layer of foam, top layer, or both. In certain embodiments, the adhesive may be applied to the central longitudinal elongate member of the stabilizing structure rather than to the tabs or other location. By applying adhesive only to the central elongate member, the stabilizing structure may collapse without resistance from the foam.

FIGS. 20A-D show embodiments of wound closure devices where the bottom foam is larger than the top foam, either by width, length, or both. Here, the foam extends outward from the stabilizing structure to create a lip, thereby allowing the lip of foam to extend above or below the surrounding tissue layers such as the fascia. The lip may serve to maintain the stabilizing structure in place by providing a downward force to resist the upward force applied by the expanding underlying viscera. In certain embodiments, the lip may need to be folded during placement within the wound bed so as to allow the closure device to be properly positioned. Thereafter the lip may unfold and extend into the surrounding tissues to aid in securing the device and applying negative pressure to the surrounding tissues.

In certain embodiments, the wound closure device of 6350 may be dome-shaped. In certain embodiments, the stabilizing structure may be dome shaped and/or the bottom and/or the top layer of foam may be dome shaped. The stabilizing structure may be shaped such that the upper surface is concave while the bottom surface is convex. In some embodiments the upper surface of the stabilizing structure is convex while the lower surface is concave. Any of the layers of foam (the top, bottom, middle or further layers of foam) may comprise an upper surface that is concave and a bottom surface that is convex. In some embodiments, any of the layers of foam (the top, bottom, middle or further layers of foam) may comprise an upper surface that is convex and a bottom surface that is concave.

The top layer may be sized to the top of the stabilizing structure, thereby facilitating closure of the wound to the size of the collapsed stabilizing structure. The lip extending outward from the matrix may be rounded so as to provide a better fit within the wound. In contrast, in the embodiment of FIG. 20E, the bottom layer may be smaller than the top layer. The top layer may advantageously prevent drawing of the drape down into the stabilizing structure or between the stabilizing structure and the edges of the wound.

In certain embodiments, the foam layers may be of any thickness disclosed herein this section or elsewhere in the specification. The bottom layer of foam 6354 may be approximately 15 mm thick or approximately 10 mm thick. For example, the bottom foam 6354 of FIG. 20D is thicker than the bottom foam of FIG. 20C.

FIGS. 20F-20G depict an embodiment of a wound closure device involving a total of 3 layers of foam. Here, wound closure device 6350 comprises stabilizing structure 6302, top layer of foam 6352, bottom layer of foam 6354, and middle layer of foam 6356. The stabilizing structure may be pre-attached to the middle layer of foam, top layer of foam, or both. Further, the bottom layer of foam may be pre-attached to the middle layer of foam, or may be placed into the wound separately. In some embodiments, the top layer is 15 or 10 mm thick, the middle layer is 15 mm thick, and the bottom layer is 10 mm thick. Foam layers may be attached by any suitable means, such as via adhesive or anchors. As depicted in FIG. 20E, the bottommost layer of foam may comprise a lip that extends outward from the wound closure device into the surrounding tissue. As described above, such a lip may secure the device in place. The bottom layer of foam may be wider and/or longer than the middle and/or top layers of foam. In certain embodiments, in addition to the foam on the top and bottom of the stabilizing structure, foam may be attached to the entire outer perimeter of the stabilizing structure. Foam may be attached to the perimeter of the stabilizing structure via any suitable means, such as by adhesive or anchoring layer. Once foam has been applied to the perimeter of the stabilizing structure, the stabilizing structure will no longer be visible if there are also top and bottom layers of foam.

In embodiments of the foam layers of FIGS. 20A-20F, the layers of foam may comprise any type of suitable foam material described herein this section or elsewhere in the specification. For example, the foam may comprise “black foam” such as polyurethane and/or “white foam” comprising polyvinyl alcohol (PVA). In embodiments involving PVA foam, thinner foam layers may be needed as compared to other types of foam, because PVA foam is often more resilient and dense than other types of foam. Further, once PVA foam becomes wet it may also aid with lateral slip. In some embodiments, the foam layers may be combined with other fillers such as gauze, or other mesh/net products such as those on Fry and Kossel.

FIG. 21 is a photograph of an embodiment of a foam layer 4600 that may be used in combination with any of the stabilizing structures or wound closure devices described in this section or elsewhere in this specification. The foam layer of 4600 may be used in place of any foam layer described herein this section or elsewhere in the specification. As described in this section and elsewhere in the specification, the foam layer 4600 may be located above or below the stabilizing structure or wound closure device. In some embodiments, the foam layer 4600 is located both above and below the stabilizing structure or wound closure device. The foam layer 4600 can surround the perimeter of the stabilizing structure or wound closure device or completely surround the entirety of the stabilizing structure or wound closure device. The foam layer 4600 can be constructed from absorbent materials, materials configured to distribute fluid, or both.

The foam layer 4600 further comprises fingers 4602 that can extend from the foam layer into the stabilizing structure or closure device. For example, the fingers 4602 may extend into and around the gaps or cells depicted in the stabilizing structures described herein this section or elsewhere in the specification. The fingers 4602 may also extend around the outside of the perimeter of the stabilizing structure. In some embodiments, the fingers 4602 from one foam layer 4600 may extend through the interior or around the outside of the stabilizing structure to meet the fingers 4602 from a second foam layer 4600. Thus, one foam layer will be facing finger-side up, while a second foam layer may be facing finger-side down.

In some embodiments, the foam layer 4600 can have perforations or pre-cuts to allow portions of the foam layer 4600 to be easily torn away to shape the foam for a particular wound. In some embodiments, the fingers 4602 can extend at least about 1 mm from the surface of the foam layer, at least about 3 mm from the surface of the foam layer, at least about 5 mm from the surface of the foam layer, at least about 7.5 mm from the surface of the foam layer, at least about 10 mm from the surface of the foam layer, at least about 12.5 mm from the surface of the foam layer, at least about 25 mm from the surface of the foam layer, at least about 17.5 mm from the surface of the foam layer, at least about 20 mm from the surface of the foam layer, at least about 25 mm from the surface of the foam layer, or more than 25 mm.

In certain embodiments, the fingers 4602 can be varied so as to control the collapse of the stabilizing structure. For example, when a finger is extended into a particular cell of the stabilizing structure, the finger will prevent collapse of that particular cell. Therefore, a larger number of foam fingers extending into the stabilizing structure will reduce collapse more than a lesser number of foam fingers. For example, the fingers may extend into at least about: 10%, 20%, 30%, 50%, 75% or even 100% of the cells of the stabilizing structure, thereby further limiting collapse of the stabilizing structure.

FIGS. 22A-22E depict foams suitable for printing instructions. When placing a wound closure device such as those described herein this section or elsewhere in the specification, it may be difficult for the clinician to determine the proper orientation of the foam layer or other components of the wound closure device. Therefore, printing of symbols on the foam may make it easier for the clinician to properly orient the foam layer. Although not shown, any of the symbols or printing disclosed herein this section or elsewhere in the specification may be applied to different structures of the wound closure device, such as the stabilizing structure.

FIG. 22A depicts a simple unlabeled oval of foam 6400, such a layer provides little guidance for the proper orientation of the foam in the wound other than the general shape of the foam. FIG. 22B depicts an embodiment of a foam layer comprising horizontal stripes 6402. These horizontal stripes may be aligned along the shorter axis of a wound, thereby providing for ease of placement of the foam oval 6400. Similarly, FIG. 22C depicts an oval foam layer comprising longitudinal stripes 6404 which may be aligned with the longitudinal axis of the wound. FIG. 22D is similar to FIG. 22B, in that the horizontal arrows 6404 indicate alignment with the horizontal axis of the wound. Lastly, FIG. 22E combines the longitudinal stripes 6404 with the horizontal arrows 6404, but further includes “head” 6408 and “feet” 6410 symbols to direct the clinician to orient the head towards the head of the patient and the feet towards the feet of the patient.

In certain embodiments, foam layers similar to the foam layers of FIGS. 22B-E may include printing on one or both sides of the foam layer to indicate to the clinician which side of the foam or wound closure device is the top and which side is the bottom. Printing that precisely delineates the top, bottom, and orientation of the device may prevent a clinician from placing the wound closure device in a wound upside down or rotated in the wrong direction.

FIG. 23A is a data table that tracks the collapse (as measured by a decrease in width) of an embodiment of a wound closure device incorporating stabilizing structures similar to the structures of FIGS. 2A-3E and 16-20F, while the device is subjected to increasing levels of vacuum. Here, foam was attached to the top and the bottom of a stabilizing structure, similar to the embodiments of FIGS. 20A-20F and entire device was placed within an animal model. The vacuum was increased from 40 mm Hg to 200 mm Hg. The pre vacuum width of the device was 123.4 mm, which decreased to 83.4 mm under vacuum. FIG. 23B displays the experimental data of FIG. 23A in the form of a bar graph.

Various sensors may be placed within any of the stabilizing structures or foam layers described herein this section or elsewhere in the specification. For example, a pH, temperature, pressure sensor, or any other suitable sensor may be embedded within the stabilizing structure and/or within a foam layer. Such embodiments will advantageously allow a clinician to skip the step of removing a sensor within the wound bed, as the sensor simply be removed upon removal of the stabilizing structure or foam.

The Wound Closure Systems and Apparatuses of FIGS. 24-31

FIGS. 24-31 depict a series of embodiments of a stabilizing structure similar to the stabilizing structures disclosed previously in FIGS. 2A-2C, 12A, FIGS. 16, 17A-20F. In certain embodiments, the topmost portion of a stabilizing structure may be coated with a dissolvable material, such as along some or all of the top surfaces of any of the embodiments described herein, and/or the top edges of the walls of the cells within the stabilizing structure. In certain embodiments, some or all of the bottom and/or the interior surfaces of the stabilizing structure may additionally or alternatively be coated in the dissolvable material. Coatings may be provided on various surfaces with different thicknesses. In embodiments, the dissolvable material may be a dissolvable polymer or other suitable dissolvable material such as a natural material. For example, plant-based carboxymethyl cellulose may be suitable as a dissolvable material. Such materials are used as part of the NASASTENT nasal dressing sold by Smith & Nephew, Inc.

Described in detail below in relation to FIGS. 25-31, the dissolvable material may serve to prop open the stabilizing structure while the dissolvable material is in a solid form, preventing the stabilizing structure from collapsing under negative pressure or other means. In some embodiments, the dissolvable material may not prevent all collapse under negative pressure, but may provide a desired amount of resistance to collapse under negative pressure. Therefore, the stabilizing structure may remain in an open or partially open conformation while undergoing negative pressure according to any of the methods described herein this section or elsewhere in the specification. However, in embodiments, the dissolvable material may dissolve upon coming into contact with wound exudate drawn from the wound, or in response to external influence such as the application of heat or energy, via any of the methodologies described herein this section or elsewhere in the specification. Once the dissolvable portions dissolve, then the stabilizing structure is no longer propped open and therefore may partially or fully collapse.

In certain embodiments, as will be described in greater detail below, dissolvable material may prevent the stabilizing structure from collapsing and returning to a different shape due to the propensity of the structure to collapse to a relaxed original state, rather than due to the application of negative pressure. One of skill in the art will understand that the embodiments described below may collapse due to negative pressure, pressure from the surrounding tissue, and/or a propensity of the stabilizing structure to collapse to an un-tensioned, relaxed state.

As the dissolvable material dissolves over time, the stabilizing structure may collapse to a greater and greater extent. In embodiments, the dissolvable material may mechanically prevent collapse by being present within the cells of the stabilizing structure, thereby physically blocking the cells from collapse. In certain embodiments, the dissolvable material may be located in the corners of the cells where a small amount of dissolvable material may prevent collapse of the cell. In embodiments, the dissolvable material may coat the entirety of a single side of a cell, two sides, three sides, or all four sides of a cell. The dissolvable material may completely fil the entire space of the cell.

In certain embodiments, the dissolvable material may dissolve almost instantaneously upon interaction with wound exudate, while in some embodiments, the dissolvable material may dissolve within about: one minute, five minutes, 10 minutes, 15 minutes, 30 minutes, 60 minutes, 4 hours, 8 hours, 12 hours, 24 hours, 48 hours, 72 hours, 1 week, 2 weeks, or more than 2 weeks. As the dissolvable material dissolves along a particular timescale, the stabilizing structure may collapse accordingly.

As described previously in relation to FIGS. 10A-11B, 12B-14C, 15A-15E, and 20A-22E, foam layers may be used in conjunction with the stabilizing structures. Such foam layers may be placed singly or in multiple layers above and/or below and/or around the stabilizing structures disclosed herein this section and elsewhere in the specification. In embodiments, the foam layers may be at least partially coated in dissolvable material such as described herein this section or elsewhere in the specification. The dissolvable material may coat at least a portion of or the entirety of a top side, a bottom side, or both a top and a bottom side, leaving the side periphery of the foam layer uncoated. In embodiments, the dissolvable material may completely encase the foam layer or the dissolvable material may coat only the outer side periphery of the foam. Before coating with the dissolvable material, the foam may be compressed, such that after dissolution of the dissolvable material the foam expands to the original shape. In some embodiments, the foam itself may be constructed of dissolvable material such as disclosed herein this section and elsewhere in the specification. The foam may comprise a mixture of non-dissolvable and dissolvable foam such that the foam layer is about: 10% dissolvable, 20% dissolvable, 30% dissolvable, 40% dissolvable, 50% dissolvable, 60% dissolvable, 70% dissolvable, 80% dissolvable, or 90% dissolvable.

FIG. 24 depicts a side view of stabilizing structure 7002. The topmost portion of the stabilizing structure may be coated in a layer 7004 of dissolvable material, such as along some or all of the top surfaces of any of the embodiments described herein, and/or the top edges of the walls of the cells within the stabilizing structure. In certain embodiments, some or all of the bottom and/or the interior surfaces of the stabilizing structure may additionally or alternatively be coated in the dissolvable material. Coatings may be provided on various surfaces with different thicknesses. In embodiments, the dissolvable material may be a dissolvable polymer or other suitable dissolvable material such as a natural material. For example, plant-based carboxymethyl cellulose may be suitable as a dissolvable material. Such materials are used as part of the NASASTENT nasal dressing sold by Smith & Nephew, Inc.

As shown in FIG. 24, a stabilizing structure 7002 may be overlain with heating elements 7005, connected to other components via a wire 7006. Such heating elements may provide energy in the form of heat to aid in dissolution of the dissolvable materials described herein this section or elsewhere in the specification.

FIGS. 25A-D depict a sequence of manufacture and dissolution for a portion of a stabilizing structure 7008. The stabilizing structure can have a plurality of cells provided in any of the arrangements and with any of the shapes described elsewhere in the specification. Therefore, although the cells shown in FIGS. 25A-D have four sides and are generally diamond-shaped, and only a few representative cells are illustrated, other cell shapes and arrangements can be utilized.

FIG. 25A illustrates the stabilizing structure 7008 in a top view, which may be first constructed with its cells at least partially closed, such as in a mold where the cells are formed to be partially closed when in a relaxed state. During manufacture, tension may be applied to stretch the stabilizing structure into an open conformation 7010, as depicted in FIG. 25B. For example, tension may be applied parallel to the horizontal plane of the stabilizing structure and along its transverse axis to increase the width of the stabilizing structure. In certain embodiments, tension may be applied perpendicular to the horizontal plane of the stabilizing structure. Such a stabilizing structure may be elastic, thus there may be a retractile force of the structure itself to rebound back to the original shape as formed in the mold.

As depicted in FIG. 25C, dissolvable material 7011 may then be applied to the stabilizing structure to coat the stabilizing structure, for example along internal surfaces of the cells of the stabilizing structure, and prevent collapse of the structure, such as via mechanical means. Dissolvable material may be applied to internal corners of the cells of the stabilizing structure. In some embodiments, dissolvable material is applied only to opposite corners of a cell along the longitudinal axis of the cell. In certain embodiments, the dissolvable material may be applied to one, two, three, and/or four corners of an individual cell. Different individual cells may have different numbers of corners filled by dissolvable material

As shown in the bottom-most image, FIG. 24D, during manufacture the cells of the stabilizing structure may spring back to a partially closed state, where the dissolvable material prevents the stabilizing structure from further collapse. In certain embodiments, the stabilizing structure may be placed in a wound of a patient in this configuration. In embodiments, the dissolvable material can extend from the top to the bottom of a cell and/or along a portion.

After the stabilizing structure is placed in a wound, as the dissolvable material dissolves, the internal angle of the corners where dissolvable material is applied decreases over time, for example as depicted in FIGS. 26A-D. As described previously in FIGS. 25A-D, the dissolvable material may prevent collapse of the stabilizing structure over a particularly timescale, thereby delaying the return of the stabilizing structure to its original shape 7012.

FIGS. 26A-D depict an embodiment of a stabilizing structure 8000 similar to the stabilizing structures described previously in relation to FIG. 25A-D, illustrating schematically opposing wound edges 8001 and a portion of a stabilizing structure that may be positioned inside a wound between the wound edges. For illustrative purposes, FIGS. 26A-D only depict part of a stabilizing structure in a top view along a horizontal cross-section, but it will be appreciated that the stabilizing structure placed between the wound edges may have any shape as described elsewhere in this specification. The stabilizing structure 8000 may comprise a textured and/or biocompatible surface 8002 configured to interact and/or integrate with and adhere to the surrounding tissue 8001. For example, biodegradable, biocompatible, and/or porous materials may be provided along all or part of the perimeter of the stabilizing structure. For example, suitable polymeric materials may comprise polylactic acids, polyglycolic acid, polyvinyl acids, or other biodegradable and/or wound compatible materials. As above, the stabilizing structure may contain dissolvable portions 8004 positioned inside the cells 8006 of the stabilizing structure, the dissolvable portions 8004 configured to prevent the stabilizing structure from collapsing initially.

Comparing FIG. 26A to 26B, over time outer surfaces or edges 8002 of the stabilizing structure may allow or promote ingrowth with the wound edges 8001. Over time the dissolvable portions 8004 may dissolve, as shown in FIG. 26C, thereby allowing the stabilizing structure 8008, 8010 to collapse and draw the surrounding tissue together 8012 allowing the leading edges of the surrounding tissue to potentially reintegrate. The cells 8006 (comprising the elongate strips and intervening members described elsewhere in the specification) of the stabilizing structure may be constructed of a dissolvable material that dissolves on a slower timescale than the dissolvable portions, as shown in FIG. 26D, thereby allowing the entire structure to dissolve over time as it draws the tissue edges 8012 together. In some embodiments, the dissolvable portions 8004 dissolve at least about twice as fast as the cells, five times as fast, 10 times as fast, 20 times as fast, 50 times as fast, or more than 100 times as fast as the stabilizing structure.

FIGS. 27A-B depict closer views of adjacent cells of a stabilizing structure 8100 with dissolvable portions similar to the stabilizing structures and dissolvable portions depicted in FIGS. 25-26. Here, the dissolvable portions 8102 may be coated on the inside of individual cells 8104 of the stabilizing structure. As depicted in FIGS. 26-30, the label “A” in these figures indicates the walls of the cells, such as viewed from the top of the stabilizing structure or in a horizontal cross-section, and “B” indicates the dissolvable material, such as described herein this section or elsewhere in the specification. In certain embodiments, “A” may also be dissolvable, but the materials designated as “B” are relatively more dissolvable than those labeled as “A.” As illustrated in FIG. 27B, in some embodiments only some of the internal corners of the cells of the stabilizing structure may be coated to promote preferential collapse. In certain embodiments, the structure A may be notched in the corner to allow for a greater amount of material “B” to be present. In certain embodiments, the entire inner faces of the cells may be coated in dissolvable material. Over time, the dissolvable portions break down and become smaller and smaller 8106, thereby allowing the stabilizing structure to collapse further. As in the embodiments of the stabilizing structure depicted in FIG. 25, the cells of the stabilizing structure may also be dissolvable, albeit at a slower timescale than the dissolvable portions. However, in alternative embodiments, the cells may dissolve more quickly than the dissolvable portions at any rate or relative rate described herein this section or elsewhere in the specification.

FIG. 28 depicts an inner wall of a stabilizing structure similar to the stabilizing structures depicted previously in FIGS. 24-26 in a top view or in a horizontal cross-section. Here, the wall 8200 may be molded to be curved and/or domed in shape in a relaxed position, but may then be straightened 8202 and placed under tension by filling crenulations 8204 with dissolvable materials 8206. Similar to the stabilizing structures described above, such a wall may return to the original domed and/or curved shape over time while the dissolvable portions 8206 dissolve. In certain embodiments, the crenulations 8204 may be present on the top and/or bottom and/or sides of the stabilizing structure.

FIG. 29 depicts a close-up view of an alternative embodiment of a repeating structure of a stabilizing structure 8300 in a top view or in a horizontal cross-section, similar to those stabilizing structures depicted previously. Here, the repeating pattern of both the cells 8302 of the stabilizing structure and the dissolvable portions 8304, while in a tensioned position 8300, is that of repeating abutting circular structures, the circular cells 8302 connected to one another by a connecting portion 8304. However, once the dissolvable portions dissolve according to any of the rates or methods described herein, the cells of the stabilizing structure rotate from a circular conformation to a straight or substantially straight more grid-like conformation 8308. In some embodiments of the repeating structure 8310, the dissolvable portions 8312 abut the circular cells 8314 not at the rounded edges but at the open side of a half-circle connected to another circle or half-circle by a connecting portion 8316.

FIG. 30 depicts a close-up view of the top of a stabilizing structure 8400 (or in a horizontal cross-section), similar to the stabilizing structures depicted above in FIGS. 2A-2C, 12A, 16, and 17A-20F. Here the intervening members may include a first set of intervening members made from dissolvable materials 8402 and a second set of intervening members made from non-dissolvable or more slowly dissolvable materials 8404, the dissolvable and non-dissolvable intervening members facing each other in an opposing arrangement, each the reflection of the other. In certain embodiments, the dissolvable intervening members separate a four-sided cell into two three-sided cells. Further, in embodiments, the dissolvable intervening members can extend for less than the entire height of the cell or extend for the entire height of the cell. As will be understood by one of skill in the art, either type of intervening member 8402, 8404 may be constructed to dissolve according to any of the rates described herein this section or elsewhere in the specification, however intervening member 8402 is dissolves at least as quickly as intervening member 8404. Once the intervening members 8402 dissolve, then the stabilizing structure collapses, bringing the elongate strips 8406 together. The collapse may occur according to any rate described herein this section or elsewhere in the specification.

FIG. 31 depicts a dissolvable portion 8500 with thicker ends 8502 and a curved interior that thins toward the middle 8504. Such a dissolvable portion 8500 will dissolve completely through at the middle portion 8504 first due to the lesser mass of dissolvable material compared to the ends. Therefore, if pressure is applied inwardly at the two ends, the dissolvable portion will continue to compress together and become shorter and shorter over time 8506. Such a structure may be advantageous to prop open a stabilizing structure and control the collapse over time. In some embodiments, the dissolvable portion 8500 may be positioned within any of the cells of the stabilizing structures described herein.

Although this disclosure describes certain embodiments, it will be understood by those skilled in the art that many aspects of the methods and devices shown and described in the present disclosure may be differently combined and/or modified to form still further embodiments or acceptable examples. For example, the features of any of FIGS. 25-30 may be combined together in combination with any of the stabilizing structures described herein. All such modifications and variations are intended to be included herein within the scope of this disclosure. Indeed, a wide variety of designs and approaches are possible and are within the scope of this disclosure. No feature, structure, or step disclosed herein is essential or indispensable. Moreover, while illustrative embodiments have been described herein, the scope of any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), substitutions, adaptations and/or alterations as would be appreciated by those in the art based on the present disclosure. While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of protection.

Features, materials, characteristics, or groups described in conjunction with a particular aspect, embodiment, or example are to be understood to be applicable to any other aspect, embodiment or example described in this section or elsewhere in this specification unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The protection is not restricted to the details of any foregoing embodiments. The protection extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Furthermore, certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations, one or more features from a claimed combination can, in some cases, be excised from the combination, and the combination may be claimed as a subcombination or variation of a subcombination.

Moreover, while operations may be depicted in the drawings or described in the specification in a particular order, such operations need not be performed in the particular order shown or in sequential order, or that all operations be performed, to achieve desirable results. Other operations that are not depicted or described can be incorporated in the example methods and processes. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the described operations. Further, the operations may be rearranged or reordered in other implementations. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the processes illustrated and/or disclosed may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be removed, others may be added. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which fall within the scope of the present disclosure. Also, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products.

For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, those skilled in the art will recognize that the disclosure may be embodied or carried out in a manner that achieves one advantage or a group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or steps are included or are to be performed in any particular embodiment.

Conjunctive language such as the phrase “at least one of X, Y, and Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z.

Language of degree used herein, such as the terms “approximately,” “about,” “generally,” and “substantially” as used herein represent a value, amount, or characteristic close to the stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms “approximately”, “about”, “generally,” and “substantially” may refer to an amount that is within less than 10% of, within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of the stated amount. As another example, in certain embodiments, the terms “generally parallel” and “substantially parallel” refer to a value, amount, or characteristic that departs from exactly parallel by less than or equal to 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, 0.1 degree, or otherwise.

The scope of the present disclosure is not intended to be limited by the specific disclosures of preferred embodiments in this section or elsewhere in this specification, and may be defined by claims as presented in this section or elsewhere in this specification or as presented in the future. The language of the claims is to be interpreted broadly based on the language employed in the claims and not limited to the examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. 

What is claimed is:
 1. A wound closure device, comprising: a stabilizing structure, comprising: a plurality of cells provided side-by-side in a horizontal plane parallel to a length and a width of the stabilizing structure, each cell defined by a plurality of walls extending in a vertical direction perpendicular to the horizontal plane; a plurality of dissolvable portions positioned within the cells, the dissolvable portions configured to dissolve over time and prevent the stabilizing structure from collapsing, the stabilizing structure configured to collapse to a collapsed position after the dissolvable portions are dissolved; and wherein each cell comprises a dissolvable portion coated only on a plurality of internal corners of the cell.
 2. The wound closure device of claim 1, wherein the stabilizing structure is configured to collapse more in the horizontal plane parallel to a length and a width of the stabilizing structure than in the vertical plane perpendicular to the horizontal plane.
 3. The wound closure device of claim 1, wherein the dissolvable portions are configured to dissolve within 24 hours.
 4. The wound closure device of claim 1, wherein the cells are configured to be dissolvable.
 5. The wound closure device of claim 4, wherein the cells are configured to dissolve slower than the dissolvable portions.
 6. The wound closure device of claim 1, wherein the cells are configured to not dissolve.
 7. The wound closure device of claim 1, wherein the dissolvable portions comprise a carboxymethyl cellulose.
 8. The wound closure device of claim 1, wherein the dissolvable portions are positioned at intersections between walls within each cell.
 9. The wound closure device of claim 1, further comprising a top layer of foam positioned above the stabilizing structure.
 10. The wound closure device of claim 9, further comprising a bottom layer of foam positioned under the stabilizing structure.
 11. The wound closure device of claim 10, wherein the top layer, or the bottom layer, or both layers of foam are coated with a dissolvable material.
 12. The wound closure device of claim 1, wherein the dissolvable portions comprise thickened end portions.
 13. The wound closure device of claim 1, wherein the stabilizing structure is configured to collapse under negative pressure.
 14. The wound closure device of claim 1, further comprising a suction port configured to supply negative pressure to a wound.
 15. The wound closure device of claim 1, further comprising one or more drapes configured to cover the stabilizing structure and form a seal around a wound.
 16. The wound closure device of claim 1, further comprising a source of negative pressure.
 17. The wound closure device of claim 1, further comprising means for delivering energy to the stabilizing structure to aid in the dissolution of the dissolvable portions.
 18. The wound closure device of claim 1, wherein each dissolvable portion comprises a first dissolvable portion and a second dissolvable portion coated on opposite corners of the cell along a longitudinal axis of the stabilizing structure. 